Polymorph trap

A polymorphtrap changes you to a new species, in the same manner as a polymorph spell, potion or wand. They will not be generated on dungeon levels 1 to 7.[1] The only guaranteed polymorph trap is on the wizard quest locate level.

Effects

If you are wearing dragon scales or dragon scale mail, you turn into that color dragon.[2] If you were also wearing a cloak, it will be ripped apart (destroyed). Wearing gray dragon scale mail will prevent the polymorph from happening.

If you have lycanthropy, you switch between your animal and were forms.[3]

Otherwise, you have a (19-Con)/20 chance of suffering a system shock: you sustain d30 damage and abuse your constitution.

If none of the above happened, you either polymorph into a random monster for 500-999 turns,[5][6] shorter if your polymorphed level is higher than your native level, or if you polymorph into your own race and see: "You feel like a new <race>". This redistributes your attributes and changes your experience level by up to two levels.

This transformation will destroy your shirt, body armor and cloak if you polymorph into something large or bigger, a non-humanoid medium or bigger, or a gargoyle or marilith (wings and extra arms don't fit).

The trap then disappears.

Monster usage

A user has suggested this page be merged with "the messages here apply generally to monster polymorph, not just poly traps (e.g. chameleons, lycanthropes can generate these). This section needs to be reconciled to [[polymorph]] "

If a monster uses a polymorph trap, you can sometimes hear it from
anywhere on the level:

A monster polymorphed into something too big or the wrong shape for its body armor, and the armor was destroyed.

"You hear a ripping sound."

A monster's shirt or cloak was destroyed as it polymorphed into something too big.

However, these messages can also originate from lycanthropes.

A polymorph trap turns a monster into any of 269 equally likely, non-human, non-limited edition species.[7][8][9]

Monsters can resist polymorph traps.[10] Polymorph traps count as a wand for these purposes (level 12).

Monsters may deliberately jump onto polymorph traps if their difficulty is at most five, or simply blunder onto them.[11][12][13] Even if monsters deliberately jump onto the trap, they still have the large chance to become out-of-depth monsters, as opposed to monsters using items of polymorph.[14]

If you do not have magic resistance, there are other ways to reliably protect yourself from polymorph traps. Wearing a ring of polymorph control is good protection against polymorph traps, as you can always choose a safe form into which to polymorph. An amulet of unchanging will also protect you from transforming. Wearing disposable junk armor while searching the level is a less desirable alternative if you must explore below dungeon level 7 without magic resistance.

The presence of out-of-depth monsters, or unusual, Gehennom-only, or non-randomly generated monsters such as woodchucks, is a likely indicator of a polymorph trap on the level. If several unusual monsters are grouped in a single area a polymorph trap is almost certainly nearby; check this with telepathy. Proceed with caution.

If you are immune to being polymorphed, you can displace your pet onto the trap to have it turn into a random monster. You can keep doing this until your pet is something useful or powerful, or turns into a (baby) gray dragon, at which point it too is magic resistant, and is no longer affected by the trap. If you aren't immune to being polymorphed, consider using a leash on your pet and standing next to a polymorph trap. Chances for a pet to walk over the trap are much higher this way. Another way is to push boulders to make a two square trap and thus forcing your pet to move between the trap and an empty space. After a desirable morph is reached, you can block the trap with a boulder.

You can also use a magic whistle to make your pet land on the trap until you get a desirable morph or a gray dragon. Combine the polymorph trap and magic whistle with some pet treats like tripe or a horse friendly treat like an apple and you can get a pretty nice pet. Note: pets that eat in your presence tend to stay tame longer. The winged gargoyle is a great pet, but it doesn't eat. Standing on the trap and displacing the correct pet onto it works best. Each move, you have 6/7 chance of swapping places (never if it's a long worm or you are punished),[15] 1/7 chance if it is sessile.[16]

If you have neither magic resistance nor a magic whistle, you have no way to cause a sessile pet to be polymorphed by the trap; generating one of these (such as a blue jelly), would end the attempt, but at least protect the trap from other monsters.

If your pet is polymorphed into a pudding, you may want to try to split it, possibly yielding more pets to polymorph. As the name is cloned along with it, you may want to rename one. See Abuse for ramifications of attacking and splitting your pet. Follow the usual advice on splitting puddings if you are not familiar; doing this carelessly is an easy way to accidentally kill your pet.

Polymorph traps are a resource, but they can also be quite dangerous if you leave them lying around unprotected (some weak but intelligent monsters will willingly jump into the trap to become something stronger (luckily including pets), which can be a Bad Thing depending on how much stronger it becomes). You can protect a polymorph trap by dropping an item and engraving Elbereth on it. This will prevent most monsters from stepping onto the trap. Alternatively, if you don't have protection from the trap, you can drop an item and engrave Elbereth on each tile adjacent to the trap. You can also dig down on the polymorph trap with a pick-axe: since only one trap can exist on a square, the resultant pit will remove the polymorph trap. Pushing a boulder on the trap will only protect it from most monsters – notably, very small ones can still use it. (In case no boulders are handy, you can make a boulder fall down stairs by throwing a non-rock object onto it.)